Final answer:
In a single day, 120 airplanes originating in New York City will pass airplanes originating in Los Angeles in the air, given that flights depart every hour and each flight takes 5 hours.
Step-by-step explanation:
To determine how many airplanes that originated in New York City will pass airplanes originating in Los Angeles in the air, we can start by noting that flights leave each city every hour on the hour. Given that each flight takes 5 hours, an airplane leaving New York City at any given hour will pass 5 airplanes from Los Angeles - one plane that left Los Angeles 1 hour ago, one that left 2 hours ago, one that left 3 hours ago, one that left 4 hours ago, and one that just left Los Angeles at the same hour.
Since there are 24 hours in a day and an airplane leaves New York City for Los Angeles every hour, 24 New York City flights will depart in a single day. Each of these flights will pass 5 Los Angeles airplanes. Therefore, the total number of passing events is 24 (departures from New York City) times 5 (passing Los Angeles planes), which equals 120.